Custom domains, GH-pages, Cloudflare and strict SSL end-to-end encryption

Why I wrote this

Before Github supported SSL encryption for github pages sites, many people were using CloudFlare (CF) as their DNS provider and CDN proxy. CF allowed users to enable SSL encryption from the CDN end points/proxies to the end user. This was great and it allowed visitors to your website to connect with a secure connection between their browser and the cloudflare CDN box that was serving your content. However, with this setup one (significant) link in the chain remained unencrypted and